Antibiotics Mechanisms Flashcards

1
Q

The Minimal Inhibitory Concentration (MIC) defines the minimum dose needed for an antimicrobial to do what?

A

Be bacteriostatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the most common mechanism by which antibiotics inhibit or kill bacteria?

A

Interference with cell wall synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the 2nd most common mechanism by which antibiotics inhibit or kill bacteria?

A

Interference with protein synthesis (targets the bacterial ribosome)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a common mechanism by which antifungals work?

A

Inference with cytoplasmic (plasma) membrane function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The bacterial cell wall is synthesized by cross-linking peptidoglycan strands using what enzymes?

A

Penicillin Binding Proteins (PBPs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

State the mechanism of action and whether the agent is static or cidal: Penicillin

A

Interference with cell wall synthesis; bacteriocidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

State the mechanism of action and whether the agent is static or cidal: Cephalosporins

A

Interference with cell wall synthesis; bacteriocidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

State the mechanism of action and whether the agent is static or cidal: Glycopeptides / Vancomycin

A

Interference with cell wall synthesis; bacteriocidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

State the mechanism of action and whether the agent is static or cidal: Macrolids

A

Interference with protein synthesis; bacteriostatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

State the mechanism of action and whether the agent is static or cidal: Tetracyclines

A

Interference with protein synthesis; bacteriostatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

State the mechanism of action and whether the agent is static or cidal: Fluoroquinolones

A

Interference with nucleic acid synthesis; bacteriocidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

State the mechanism of action and whether the agent is static or cidal: Aminoglycosides

A

Interference with protein synthesis; bacteriocidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

State the mechanism of action and whether the agent is static or cidal: Sulfonamides + Trimethoprim

A

Interference with metabolic pathways; bacteriocidal (sulfonamides are static, but trimethoprim is cidal so together they are cidal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the 4 classes of beta-lactam antibiotics?

A

Penicillins, cephalosporins, monobactams, carbapenems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Name 3 advantages of beta-lactams.

A

Non-toxic, cheap, and mostly water-soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Specifically, how does a beta-lactam inhibit cell wall synthesis?

A

It irreversibly inhibits the penicillin binding protein / transpeptidase by mimicking the D-Ala-D-Ala residues that would normally bind there

17
Q

Specifically, how does a glycopeptide inhibit cell wall synthesis?

A

It binds to the D-Ala-D-Ala residues of a peptidoglycan strand, thus preventing the strand from cross-linking

18
Q

Specifically, how does a macrolid inhibit protein synthesis?

A

It binds to the bacterial ribosome, blocking the exit of the growing peptide chain

19
Q

Specifically, how does a tetracycline inhibit protein synthesis?

A

It prevents the tRNA-aa complex from attaching to the ribosome

20
Q

Specifically, how does a fluoroquinolone inhibit nucleic acid synthesis?

A

It inhibits DNA gyrase and DNA topoisomerase

21
Q

Specifically, how does an aminoglycoside inhibit protein synthesis?

A

It changes the shape of the bacterial ribosome so that mRNA is read incorrectly

22
Q

Specifically, how do sulfamethoxazole and trimethoprim (often given together as TMP/SMX) interfere with metabolic pathways?

A

Sulfamethoxazole competes with PABA while trimethoprim inhibits DHF reductase, together preventing folic acid synthesis

23
Q

Ampicillin, amoxicillin, and piperacillin are examples of what class of beta-lactam?

A

Penicillin

24
Q

Cefotaxime, ceftriaxone, and cefipime are examples of what class of beta-lactam?

A

Cephalosporin

25
Compared to 1st generation cephalosporins, do 3rd generation cephalosporins have better or worse activity against Gram(+) and Gram (-) bacteria?
3rd gen has better Gram (-) activity, worse Gram (+)
26
Vancomycin is an example of what kind of cell wall inhibitor?
Glycopeptide
27
Are glycopeptides and lipoglycopeptides more effective against Gram (+) or Gram (-) bacteria?
Gram(+) - they can't get through the porins of Gram (-) bacteria to attack their cell walls
28
Gentamycin, tobramycin, and amikacin are examples of what kind of protein synthesis inhibitor?
Aminoglycoside
29
Erythromycin and azithromycin are examples of what kind of protein synthesis inhibitor?
Macrolid
30
Ciprofloxacin, levofloxacin, and norfloxacin are examples of what kind of nucleic acid synthesis inhibitor?
Fluoroquinolone